Roller bit



Dec. 29, 1953 E. G. BOICE 2,664,322

ROLLER BIT Filed Oct. 9, 1950 2 Sheets-Sheet l f/vm 6. Bo/ce INVENTOR.

ATTORNEY-S Dec. 29, 1953 E. G. BOICE ,322

ROLLER BIT Filed Oct. 9, 1950 2 Sheets-Sheet 2 Ely/n 6. Bo/ce INVENTOR.

Patented Dec. 29, 1953 ROLLER BIT Elvin G. Boice, Houston, Tex.,assignor to Reed Roller Bit Company, Houston, Tex., a corporation ofTexas Application October 9, 1950, Serial No. 189,264

Claims.

This invention relates generally to roller bits for deep well drilling,and particularly to a roller bit having a new and improved bearing forthe roller cuttersthereof. Conventional roller bits for the drilling ofoil wells include a bit head in which are mounted roller cuttersprovided with teeth to penetrate the formation when the head is rotatedby the usual drill stem. During drilling operations, the bearing of theroller cutters are subjected to very great shocks and strains ineludingdestructive end thrusts. The bearings are also subjected to the abrasiveaction of mud-1aden fluid which is pumped downwardly through the drillstem and bit and rises upwardly in the space between the drill stem andthe wall of the well to keep the cutters cool, to remove the cuttings,and to perform other functions well-known to those skilled in the art.

This invention has for one of its objects to provide a rollerbit withnew and improved end thrust bearings, the parts of which may be quicklyand easily assembled.

Otherobjects will hereinafter appear.

The preferred embodiments of the invention are illustrated by theaccompanying drawings, in which Fig. l is a fragmentary partly sectionalview of a cross roller bit illustrating the use of one embodiment of theinvention in the side roller cutter thereof; and

Fig. 2 is a sectional view (on a reduced scale) on the line 2-2 of Fig.1.

Fig. 3 is another embodiment of the invention in the side roller cutterof the cross roller bit; and

Fig. 4 is a section (on a reduced scale) on the line 44 of Fi 3.

Referring to Fig. l, the lower portion of the cross roller bit head isindicated at I, the cross roller cutter at 2 and the side roller cutterat 3.

The head I is provided with a downwardly and inwardly inclined shaft 4having a bore 5 for the reception of the pin 5 of the bridge 5, whichpin is welded in place as indicated at t-a. Between the shaft 4 and theside roller cutter 3 are load hearing rollers I and 8. The numeral 9indicates my new and improved end thrust bearing rollers which in thisembodiment are tapered substantially from end to end to bear against theinward- 1y tapered side walls Id of the raceway of the shaft 4 andagainst the inwardly tapered side walls I I of the raceway of the cutter3, as shown by Fig. l; and against each other as shown by 2. Within theshaft raceway defined by the tapered side walls It are a plurality ofspring rings I2 which serve to yieldably urge the end thrust bearingrollers 9 outwardly into their operative positions. The bearing rollers3 are insertable into the raceways of the cutter 3 and shaft 4, definedby the walls II and It, through an opening I 4 against the resistance ofthe spring rings I2 which are normally of a-diameter greater than thatshown by Figs. 1 and 2 and which are compressed to a smaller diameterwhen the end thrust rollers 9 are thus inserted. After each roller 9 isinserted through the opening It in the cutter against the resistance ofthe spring rings t, it may be moved laterally in the raceways to makeroom for the roller to be inserted next. When all of the rollers 9 havebeen inserted the parts are in the relativepositions shown by Figs. 1and 2. The opening I4 may be then closed by a plug it welded in place asindicated at It.

In Figs. 3 and 4, the numerals I through 3 indicate parts similar tothose shown by Figs. 1 and 2., In the embodiment shown by Figs. 3 and 4however, the end thrust rollers Il instead of being taperedsubstantially from end to end are provided with an inner tapered portionIi-a and an outer substantially cylindrical portion Ii-b, and the sidewalls I8 of the shaft 4 are inwardly tapered and the side walls 19 ofthe cutter 3 are substantially parallel so that the bearing rollers I!bear against the said side walls I8 and It as shown by Fig. 3 andagainst each other as shown by Fig. 4. The opening in the cutter 3through which the bearing rollers I1 are insertable is indicated at 20and the plug to close this opening at El welded as indicated at 22. Theopening 20 is provided with a shoulder 20-0; and the plug 2i with areduced extension 2 I-a to fit the same. The numeral 23 indicates springrings corresponding with the spring rings I2 shown by Figs. 1 and 2.

It will be apparent from Figs. 1 and 2 that the end thrust bearingrollers 9 may be inserted through the opening it of the cutter into theraceways so that they will be in a position to rotate on axessubstantially radial to the axis of rotation of the cutter 3.

It will also be apparent that when the rollers 9 are inserted throughthe openings It they will compress the spring rings l2 so that duringthe operation of the bit the spring rings l2 will yield ably urge theend thrust bearing rollers 9 outwardly into their operative positions.

It will also be apparent that the tapered end thrust bearing rollers 9will roll upon the tapered side walls It of the shaft i and the taperedside walls II of the cutter 3, and that said tapered rollers 9 willroll'upon each other and that this will provide a good bearing betweenthe rollers and between the rollers and the walls of the raceways, toefficiently sustain the end thrust on the cutter 3.

The invention is not limited to the preferred embodiments hereindisclosed. Various changes within the scope of the following claims willbe apparent to those skilled in the art.

I claim:

1. A bit having a shaft; a roller cutter rotatable on said shaft; saidshaft having a raceway with inwardly tapered side walls, said cutterhaving a raceway with inwardly tapered side walls, thrust bearingrollers in said raceways, rotatable on axes substantially radial to theaxis of rotation of said cutter, and being tapered substantially fromend to end to bear against each other and against the tapered side wallsof said shaft raceway and said cutter raceway; a plurality of springrings in said shaft raceway to urge said rollers outwardly into theiroperative positions; said cutter having an opening through which saidrollers may be inserted to compress said rings and to occupysaidraceways; means to close said opening after said bearing rollers are inplace; and load sustaining bearings on each side of said thrust bearingrollers.

2. A bit having a shaft; a roller cutter rotatable on said shaft; saidshaft having a raceway with inwardly tapered side walls, said cutterhaving a raceway with inwardly tapered side walls, thrust bearingrollers in said raceways, rotatable on axes substantially radial to theaxis of rotation of said cutter, and being tapered substantially fromend to end to bear against each other and against the tapered side wallsof said shaft raceway and said cutter raceway; a plurality of springrings in said shaft raceway to urge said rollers outwardly into theiroperative positions; said cutter having an opening through which saidrollers may be inserted to compress said rings and to occupy saidraceways; and means to close said opening after said bearing rollers arein place.

3. A bit having a shaft; a roller cutter rotatable on said shaft; saidshaft having a raceway with inwardly tapered side walls, said cutterhaving a raceway with inwardly tapered side Walls, thrust bearingrollers in said raceways, rotatable on axes substantially radial to theaxis of rotation of said cutter, and being tapered to bear against eachother and against the tapered side walls of said shaft raceway and saidcutter raceway; yieldable means in said shaft raceway to urge saidrollers outwardly into their operative positions; said cutter having anopening through which said rollers may be inserted against theresistance of said yieldable means and to occupy said raceways; andmeans to close said opening after said bearing rollers are in place.

4. A bit having a shaft; a roller cutter rotatable on said shaft; saidshaft having a raceway with inwardly tapered side walls, said cutterhaving a raceway with inwardly tapered side walls, thrust bearingrollers in said raceways, rotatable on axes substantially radial to theaxis of rotation of said cutter, and being tapered to bear against eachother and against the tapered side walls of said shaft raceway and saidcutter raceway, said outter having an opening through which said thrustrollers may be inserted, and a plug to close said opening, said plughaving a shoulder to position said plug in register with said cutterraceway.

5. A bit having a shaft, a roller cutter rotatable on said shaft,raceways in said shaft and cutter, thrust bearing rollers in saidraceways and rotatable on axes substantially radial to the axis of saidcutter, and means to yieldably urge said rollers into their operativepositions in said raceways, said cutter having an opening, and saidrollers being insertable through said opening into said raceways againstthe resistance of said yieldable means, and means to close said opening.

ELVIN G. BOICE.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,760,317 Pickin May 27, .1930 2,065,740 Reed Dec. 29, 19362,126,041 Reed Aug. 9, 1938 FOREIGN PATENTS Number Country Date 8,31 iGreat Britain 1902

